libext2fs: precompute FS UUID checksum seed

[tools/e2fsprogs.git] / lib / ext2fs / openfs.c

diff --git a/lib/ext2fs/openfs.c b/lib/ext2fs/openfs.c
index 220d954..3675518 100644 (file)
--- a/lib/ext2fs/openfs.c
+++ b/lib/ext2fs/openfs.c
@@ -144,7 +144,7 @@ errcode_t ext2fs_open2(const char *name, const char *io_options,
                goto cleanup;
        fs->image_io = fs->io;
        fs->io->app_data = fs;
-       retval = ext2fs_get_memalign(SUPERBLOCK_SIZE, 512, &fs->super);
+       retval = io_channel_alloc_buf(fs->io, -SUPERBLOCK_SIZE, &fs->super);
        if (retval)
                goto cleanup;
        if (flags & EXT2_FLAG_IMAGE_FILE) {
@@ -263,6 +263,21 @@ errcode_t ext2fs_open2(const char *name, const char *io_options,
                retval = EXT2_ET_CORRUPT_SUPERBLOCK;
                goto cleanup;
        }
+
+       /* Enforce the block group descriptor size */
+       if (fs->super->s_feature_incompat & EXT4_FEATURE_INCOMPAT_64BIT) {
+               if (fs->super->s_desc_size != EXT2_MIN_DESC_SIZE_64BIT) {
+                       retval = EXT2_ET_BAD_DESC_SIZE;
+                       goto cleanup;
+               }
+       } else {
+               if (fs->super->s_desc_size &&
+                   fs->super->s_desc_size != EXT2_MIN_DESC_SIZE) {
+                       retval = EXT2_ET_BAD_DESC_SIZE;
+                       goto cleanup;
+               }
+       }
+
        fs->cluster_ratio_bits = fs->super->s_log_cluster_size -
                fs->super->s_log_block_size;
        if (EXT2_BLOCKS_PER_GROUP(fs->super) !=
@@ -300,6 +315,8 @@ errcode_t ext2fs_open2(const char *name, const char *io_options,
                retval = EXT2_ET_CORRUPT_SUPERBLOCK;
                goto cleanup;
        }
+       /* Precompute the FS UUID to seed other checksums */
+       ext2fs_init_csum_seed(fs);
 
        /*
         * Read group descriptors